The discovery of X-rays by Rontgen in 1895 and of radioactivity by Becqueral in 1896 were followed by an early appreciation of both the damaging and therapeutic effect of ionizing radiation (including genetic effects, for which Muller later received the Nobel Prize). From this emerged radiation research, a multi disciplinary field embracing physics, chemistry, biology and medicine, all of which are used to the benefit of man. The Radiation Research Society was formed in the USA in 1952, and was followed soon after by the formation of societies in Great Britain, several countries in Europe (the Netherlands, Sweden, Poland, Germany, Italy and France), Japan, and Israel. The societies now form the International Association for Radiation Research (IARR), a component of the International Union of the Biological Sciences. The first International congress of Radiation Research was held in Burlington, Vermont, in 1958, and since them, at four-year intervals, International Congresses sponsored by the IARR have been held in England, Italy, France, Japan, the Netherlands, the United States, Scotland and Germany. The 11th congress will be held in Dublin Ireland in 1999. The multi disciplinary nature of the subject area renders these international meeting especially valuable. Physicists, chemists, biologists, and physicians interested in environmental hazards in general, cancer research, and cancer therapy in general, will meet to discuss their progress. It is appropriate that a substantial contingent of attendees be from North America, in view of the leading role of American and Canadian scientists in this field. Travel awardees for the 11th Congress will be selected by a committee of members of the Radiation Research Society representing the disciplines of Biology, Chemistry, Medicine, and Physics. Selection criteria are: Congress participation, publications in radiation research, age, professional standing, and attendance at previous Congresses (sample evaluation form included in Appendix).